Influence of pore-former charge distribution on the electrostatic properties of dipolar water chains in transmembrane ion channels
✍ Scribed by Michael B. Partenskii; Mao Cai; Peter C. Jordan
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- English
- Weight
- 418 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0013-4686
No coin nor oath required. For personal study only.
✦ Synopsis
Ah&act-The free energy, polarization and susceptibility of a linear chain of molecular dipoles modeling the water molecules in a transmembrane ion channel are computed as functions of the cation location in the channel, taking into account the influence of the channel forming peptide in a primitive fashion, by treating it as a distribution of fixed charges. The membrane is simulated by a low dielectric (+,, = 2) slab surrounded by high dielectric (6 = co) continua. For parameters representative of pamicidin, we find that water molecules -he still orientationally frozen by the field of an ion; the fixed peptide charges do not alter this major result of our previous calculation. These charges affect the free energy mainly through direct electrostatic interaction with the ion.